This invention is directed to a joint capable of rotational movement between two positions and further rotatable to a third position upon application of a predetermined force. The invention is more particularly directed to a joint which emulates the movement of the elbow or knee joints from a normal position to a hyperextended position.
Human form mannequins having articulating limbs are useful in training police officers and security personnel, as well as martial arts sport participants. Individuals use these mannequins to train themselves by making various restraining moves against the mannequin as the target which acts as a substitute for a live human target. This is generally undertaken by manipulating the limbs of the mannequin in certain specific manners as a part of a training procedure to teach proper methods for restraining an individual such as a criminal suspect or martial arts opponent.
It is important in developing useful training mannequins of this type to ensure that the articulating limbs demonstrate closely the normal functional flexion, extension and rotational positions of those limbs. Many suspect control tactics employed by law enforcement and security officers and many martial arts training programmes utilize a target""s limbs (arms and legs) as third class levers. For example the law enforcement officer or martial arts trainee could push down on the elbow joint of the target while pulling upwards on the wrist while maintaining shoulder stability. The bending and twisting of the arm and lower leg to the extreme is not a normal function of the body, but is often used by police, security personnel and martial arts practitioners in applying painful control tactics to a resisting suspect or opponent. It is important in most situations to control the level of force applied on the target individual to prevent serious injury to that individual while maintaining adequate control over that individual.
The level of appropriate force can often be difficult to control, particularly in trainees who are learning suspect control tactics or martial arts moves as these individuals do not generally have an understanding of the physical limitations of the target""s limbs in applying these forces. This can result in harm to the target through movement of the limb joint past a position which is adequate for control to a hyperextended position which causes physical damage to the target individual, including the breaking of limbs, the dislocation of the joint or stretching or tearing of ligaments in the joint. In most cases this is an undesirable consequence of target restraint tactics in a law enforcement environment and an undesirable consequence in a martial arts environment.
It is also important to appreciate that the application of force under a martial arts, and the restraining and controlling of suspects in a law enforcement and security context, varies widely with the size, strength and awareness of the target individual as well as the environment in which the force is being applied. For example, a large male individual will usually provide greater resistance to movement of a limb into a controlling position than a small female or child. The force application requirement will also vary depending on whether or not the target is alert to the possibility of a controlling tactic being applied to that individual. Taken by surprise, a target may be manipulated into a controlled position by a law enforcement or security officer with minimal force, as compared to a target who is actively resisting control.
There is consequently a need for a mannequin having articulated limbs which may be used as a target in the practise of suspect control tactics and martial arts sport and training programmes which provides realistic resistance to manipulation of the limb about the joint from any flexion or extension position to a hyperextended position used to control the target or to undertake a martial arts move, without applying excessive force which would result in serious damage to the target""s limbs or joints.
There is also a need for a mannequin having articulate limbs which are adjustable to vary the force necessary to move the limb about the joints to the hyperextended position to provide a range of training options depending on the individual characteristics of a potential suspect or martial arts opponent to be emulated by the mannequin.
This will enable enforcement and security personnel as well as martial artists to develop better knowledge through practice and training as to the amount of force reasonably required to restrain an individual using a control tactic or martial arts move, without applying excessive force to damage the limb or its joint. Such a mannequin would also permit training for law enforcement and security personnel in relatively rare emergency situations where drastic measures are required to ensure that sufficient force is applied to the limb to deliberately cause damage in order to restrain or otherwise control an individual in situations which call for excessive force.